Conventional reverse osmosis type water filters utilize reverse osmosis tubes for filtering water. The reverse osmosis tubes are very fine and a pressurizing pump is needed to pressurize a water source so that the water can flow smoothly through the reverse tubes. Usually the water is automatically supplied to the reverse osmosis filter and the water source is kept open. A water stopper valve is usually provided after the pressurizing pump so that the water can be stopped from flowing into the reverse osmosis tubes when the water in a water reservoir reaches a predetermined level, and thus water can be saved.
Please refer to FIG. 4 which shows a conventional pressurizing pump and a water stopper valve. The pressurizing pump comprises mainly a pressurizing motor 15 and a pressurizing set 10. An eccentric axle 11 is provided on the bottom of the pressurizing set 10 and operationally connected with the pressurizing motor 15 so that the water source can be pressurized because of this structure. An upper lid 50 of the pump is provided on the upper end of the pressurizing set 10. The upper lid 50 is provided with a pressurizing room 53 and formed with a water inlet hole 51 and a water outlet hole 52 on the two sides thereof. The water outlet hole 52 and the water inlet hole 51 communicate separately with the pressurizing room 53 and are separated with the pressurizing set 10 so that the water can flow from the water inlet hole 51 of the upper lid 50 into the pressurizing set 10, get pressurized in the pressurizing set 10, and flow out from the water outlet hole 52. A water stopper valve 60 is connected after the water outlet hole 52 of the upper lid 50. The water stopper valve 60 has an upper seat 68 and a lower seat 61. The two ends of the upper seat 68 communicate separately with a water source tube. The lower seat 61 is provided with a receiving groove 65 and is formed with a water inlet hole 62 and a water outlet hole 63 on the two ends thereof. The water inlet hole 62 and the water outlet hole 63 are separated with a partition plate 64 and communicate separately with the receiving groove 65 via a communicating hole 620 and a communicating hole 630. a water stopper valve set 66 having a water stopper pad 67 is provided between the lower seat 61 and the upper seat 68. When the water is being pressurized by the pressurizing set 10 of the pressurizing pump, the inlet water pressure of the water inlet hole 62 is larger than the inlet water pressure of the water inlet 69 of the upper seat 68, thus the water stopper pad 67 of the water stopper valve set 66 is pushed upwardly, and the pressurized water can enter the water outlet hole 63 through communicating holes 620 and 630 so that reverse osmosis can be done. On the contrary, when the pressurizing set 10 of the pressurizing pump stop running, the water stopper pad 67 can blockade the flow between the water inlet hole 62 and the water outlet hole 63 because the area above the water stopper pad 67 is larger than the sectional area of the communicating hole 620 of the water inlet hole 62 and because of Pascal's law. Thus the water can be prevented from continuously flowing into reverse osmosis tubes.
In the conventional pump described herein above, the upper lid of the pressurizing pump and the water stopper valve are separated and therefore the pump has relatively more parts and results in higher cost involving molding, manufacturing, and assembling. Furthermore, the total volume of the water filter is relatively large because the pressurizing pump and the water stopper valve are separated, the conventional upper lid of the pressurizing pump is less desirable because of the aforementioned drawbacks.
The inventor of the present invention has many years of experience for the manufacturing, research, and developing the pressurizing pumps of the water filters. The inventor spent a long time to do research and improvement for the pressurizing pumps in order to mitigate the drawbacks of the conventional pumps, and eventually achieves the present invention which has a water stopping structure and which is more compact and of lower cost.